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EP-3 preamp magical or just what they had at the time?

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  • #31
    Re: EP-3 preamp magical or just what they had at the time?

    Originally posted by B2D View Post
    Hey guys, just FYI the Chase preamp appears to have a discount going on. I just ordered one for $130 after shipping and they're starting price is $170 ish on Reverb.



    I'l see how I like it and whatnot... I currently have an SP compressor as an 'always on' pedal, especially for cleans. I didn't care for the EP boost that much but this does sound different to my ears, at least from clips.
    Report back! I'd love to hear from someone trying one out for the first time.

    Comment


    • #32
      Re: EP-3 preamp magical or just what they had at the time?

      Originally posted by Dave Locher View Post
      Report back! I'd love to hear from someone trying one out for the first time.
      Ship date is 2 weeks from order time. Expect a report back after then. I'm intrigued as well!

      Comment


      • #33
        Re: EP-3 preamp magical or just what they had at the time?

        For those who might be interested, I did a simulate of the actual Echoplex Preamp based on the schematic found on page 27 of this PDF.

        The Echoplex EP-3 Schematic: Serial Numbers 9451 to 12960 (from the above PDF):
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        The edited schematic minus all the delay circuitry:
        Click image for larger version

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        The equivalent schematic in LTSpice:
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        The Frequency response of the simulation:
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        Last edited by BlakeC27; 12-13-2019, 01:59 AM.

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        • #34
          Re: EP-3 preamp magical or just what they had at the time?

          BlakeC27 can you explain in layman's terms what that image shows?

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          • #35
            Re: EP-3 preamp magical or just what they had at the time?

            Originally posted by Dave Locher View Post
            BlakeC27 can you explain in layman's terms what that image shows?
            Hi Dave. Sorry I didn't actually finish this post until just now, I posted it originally last night before but had posted the incorrect images, forgot to add one, etc. But it's how I intended it to be now. The schematics are pretty self-explanatory, the top image is of the schematic of the entire Echoplex, I've then removed all the delay circuitry to show only the preamp circuit (the second image). The third image is one of the same schematic, but drawn in LTSpice (a software tool for simulating circuits) and the final image is probably the one most guitarist are interested in.

            The red line on the graph below represents unity gain; the green line is the change in the level of gain of the guitar signal across the audio spectrum with the y-axis representing the frequency (in hertz; from 10Hz up to 100Khz in this case) and the x-axis, the magnitude of the gain (in dB).

            Click image for larger version

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            The guitar signal sits just under unity gain until it hits approximately 1.1Khz and then is gradually boost to a peak of about 6.4dB at approximately 9.5Khz before steadily dropping off again. I hope that helps explains things a bit better?

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            • #36
              Re: EP-3 preamp magical or just what they had at the time?

              Thanks, BlakeC27. I'm just trying to learn! The circuit diagrams I can follow, it was the last image that confused me.

              So if I understand my quick Google search correctly, human ears hear from around 20Hz to around 20kHz.
              So in a simulated world the Echoplex preamp lowers the frequencies too low to hear by about 3dB, everything up to 1kHz by around 1-2dB, and boosts everything above that, at least within our range of hearing? Would that account for the clarity and sparkle?

              I am still trying to get my head around this "phase shift of certain frequencies" thing. Honestly I think I'm just going to have to hear it for myself to really "get" it. I hate to buy just to try but I can't figure out how else to accomplish it...

              Comment


              • #37
                Re: EP-3 preamp magical or just what they had at the time?

                That 10KHz bump explains the "chimey sheen" that I stated previously.

                It does more than just EQ curve, however. But overall the (overall) effect is subtle.

                Comment


                • #38
                  Re: EP-3 preamp magical or just what they had at the time?

                  Originally posted by Dave Locher View Post
                  I'm just trying to learn!
                  Me too.

                  Originally posted by Dave Locher View Post
                  I am still trying to get my head around this "phase shift of certain frequencies" thing.
                  Again, me too.

                  Originally posted by LLL View Post
                  That 10KHz bump explains the "chimey sheen" that I stated previously. It does more than just EQ curve, however. But overall the (overall) effect is subtle.
                  It is just that, subtle.

                  Comment


                  • #39
                    Re: EP-3 preamp magical or just what they had at the time?

                    I'm not that learned in electronics to say absolutely certainly, but there's nothing in that schematic that would make any phase shift in preamp, so I'm calling it bogus.

                    Unless scueme is wrong or someone clarifies how it should be doing it.
                    "So understand/Don't waste your time always searching for those wasted years/Face up, make your stand/And realize you're living in the golden years"
                    Iron Maiden - Wasted Years

                    Comment


                    • #40
                      Re: EP-3 preamp magical or just what they had at the time?

                      Originally posted by Dave Locher View Post
                      Thanks, BlakeC27. I'm just trying to learn! The circuit diagrams I can follow, it was the last image that confused me.

                      So if I understand my quick Google search correctly, human ears hear from around 20Hz to around 20kHz.
                      So in a simulated world the Echoplex preamp lowers the frequencies too low to hear by about 3dB, everything up to 1kHz by around 1-2dB, and boosts everything above that, at least within our range of hearing? Would that account for the clarity and sparkle?

                      I am still trying to get my head around this "phase shift of certain frequencies" thing. Honestly I think I'm just going to have to hear it for myself to really "get" it. I hate to buy just to try but I can't figure out how else to accomplish it...
                      Guitar speakers roll off after 5-6kHz range and before 55Hz I think, so a boost in the 10kHz region will be very subtle effect.

                      Comment


                      • #41
                        Re: EP-3 preamp magical or just what they had at the time?

                        Originally posted by Hank- View Post
                        Guitar speakers roll off after 5-6kHz range and before 55Hz I think, so a boost in the 10kHz region will be very subtle effect.
                        True, but the "Q"/hump (if you will) is wide and the peak is 10KHz.

                        So, 1.5,2,3,4,5,6KHz all get boosted

                        Comment


                        • #42
                          Re: EP-3 preamp magical or just what they had at the time?

                          Well look what arrived in the mail today:

                          *TC Spark shown for scale*

                          Click image for larger version

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                          I'll wire it up and play with it sometime this week. Right off the bat I can tell you that the build quality on this thing is impeccable. The printing on the pedal might be hard to read under a glaring light, but the LED is probably very bright and I suspect that this is a set-and-forget type pedal.

                          Tone report coming soon!

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                          • #43
                            Re: EP-3 preamp magical or just what they had at the time?

                            Originally posted by B2D View Post
                            Tone report coming soon!
                            Looking forward to it.

                            Comment


                            • #44
                              Re: EP-3 preamp magical or just what they had at the time?

                              Originally posted by BlakeC27 View Post
                              Looking forward to it.
                              Me too! Especially how it compares to the Spark, which I have used.

                              Comment


                              • #45
                                Re: EP-3 preamp magical or just what they had at the time?

                                Originally posted by B2D View Post
                                Well look what arrived in the mail today:

                                *TC Spark shown for scale*

                                [ATTACH=CONFIG]102720[/ATTACH]

                                I'll wire it up and play with it sometime this week. Right off the bat I can tell you that the build quality on this thing is impeccable. The printing on the pedal might be hard to read under a glaring light, but the LED is probably very bright and I suspect that this is a set-and-forget type pedal.

                                Tone report coming soon!
                                Well?? Inquiring minds want to know!!

                                Comment

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